Hey Guys

Many of you know about my T/C mod. I first went with a 3000 rpm stall speed, and then began having some pingin issues. Let me tell you upfront that the pinging issues were caused by the TC tripping up the ECU somehow.

My theory (almost fully confirmed): The high stall speed - which allowed for those insane starts - also made the TC invariably looser, thus more slippery... This means that the engine basically saw a "lighter" car, and under full load, i.e full throttle, did not reach the "full load condition" place in the ECU map. This in turn caused the ECU fuel map to be off; bear with me - this is a little complex and hard to explain here. Since the fuel map is now reading less than full throttle (car is "lighter" as the engine is loaded less because of the slipping TC) but I am applying full throttle, the full load aggressive timings maps are used while less-then full load a/f mixture is NOT used. Hence the explanation why I was running lean after my TC mod.

Solution: Todashi of TS just richened up the mixture everywhere - pinging problem went away - I started runnnig by 14.0 1/4 miles - hunky dory!, Right ? Wrong!!!

I couldn't stop thinking about the fact that I am not reaping all the benefits of a good T/C. So oops, I did it again. Had Performance Nissan (they are awesome) drop my tranny, got a POS rental car, drove my TC over to SimiValley where Bobby cut the thing apart, cut the clearance another 20/1000 of an inch to a final clearance of ONLY 15/1000 from an estimated original of 50-180/1000 of an inch (no one knows the true clearance yet - these TC just now started to be modded), lowered the stall to 2600 rpm, and I drove it back the next day and dropped it in.

Result: At first I was disappointed.. the car began to ping again - and I was saying OH SHYTE. But DaveO said to just drive it for a while, and let the air out of it. It must have been true - the air inside the AT system was making it slip right after the install. Today, 3 days later - the car pulls like a freight train!!!! The air must all be out by now - no pinging noticed today. Will have to confirm this in the next few days.

BUT HERE IS THE KICKER - HERE IS WHAT IS SO MAD ABOUT THIS. If I just place the manumatic in first gear, and proceed at a leasurely pace to about 30 mph and about 4000rpm... picturing this?... 1st gear, 4000 rpm, 30mph, and I punch the gas pedal, the engine revs with so much power and torque that I activate the VDC system and the SLIP light comes on - this is off of a 30mph rolling start!!!

I am not sure if anyone can do this in there car or not, but I sure have not seen this in mine. I am sure that the exhaust system and the rest of my mods are responsible for this also... but I bet that my TC sure is, at least in part. This is one powerful ride. God I love this car!

So the follwoing seems to be the sweetspot for the TC: 2600 rpm stall. But I cannot spins the tires like used to anymore. Oh well. That was out of control anyways... I'd rather have an efficient car then a marginally powerful one with less-then-marginal trade-off.

This is a fairly early report.. but I thought I would share it with you anyways... All the usual caveats apply...

Gurgen

P.S. One more interesting mod coming up in 2 days... I just love to be on vacation...


THIS SIG IS A LITTLE OUTDATED:

 

I'm not familiar on the torque converter so I will read up on it and see what it's all about. I can however tell you, that my VDC light has come on by itself too when I punch it hard. I think it only happened a few times, at least that I noticed.

 

KjbAlto,

Which G35 do you have? Sedan or coupe? Auto or manual transmission? Any modifications?

DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

KjbAlto,

Yeah, I want to know too, is that with an auto tranny that you could light up the SLIP indicator?

Also, a point of clarification: the SLIP doesn't just come on, the VDC is activated and the throttle is regressed a little bit. I sure have never been able to do that in my car, and my car has always been pretty well modified, with the right ECU for every mod.

Gurgen

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 12/22/03 09:14 AM.</EM></FONT></P>

 

I usually drive with my vdc off and when i push it to the limit vdcnever comes on, or alt least i dont think it does. However with vdc on and i push it to the limit i do get the slip light. I drive a 6mt.

Could you guys tell me more about the TC

 

xenon,

Suggest you do a search. Between Gurgen, Mean Gene and myself we have covered the bases pretty well. (Although not nearly as much as the continously reoccuring CAI qustions).

To get you started, the torque converter is a fluid coupling that connects the engine to an automatic transmission. It does a similar job to your 6-speed's clutch, only it multiplies off-the-line torque. Gurgen and I now have identical Street Edge Converters that increased our torque multiplication from 1.6 to over 2.2 times as well as improving the fluid energy transfer efficiency. I don't remember seeing the details of Mean Gene's TC modifications. Gene, can you help?


DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

I have an '03 coupe 6mt. It has happened a few times to me where I turned the VDC off and when I take off hard the vdc light turned on and each time it happened I was like wtf. I will try it again and see if it keeps happening. I'll let you guys know.

 

Dave - I chip in what I have. My Level 10 convertor stalled at 2800 rpms when I first got it but I had a similar situation as Gurgen & yourself. Like you, my more knowledgeable friend told me to just drive the car & allow the air to work out of the entire system. After about 3 - 4 days of hard driving, the T/C actually now stalls @ 2950 rpms! I haven't noticed any pinging as of yet ( even after the T/S reflash ) but it's been relatively cool down here ( 40 degrees is cool in Louisiana!! ).
The full throttle shifts seem a bit firmer as well via the V/B modification. I also managed to activate the "Slip" light in Gurgen's manner which takes quite a bit to spin the 11.1" wide Nittos! Full throttle takeoffs get me sideways as well - FUN!! Right now I'm trying to decide between the Tomei cams ( 264 or 268 ) plus contact Texas Nitrous for info on their throttle body injection system. I don't want to lose the extra timing the reflash gives me but Tadashi is concerned about using nitrous with the ECU as it's programmed now ( max HP for a N/A motor ). I'll install an EGT gauge & probably use some form of octane booster to see if I can have the best of both worlds! If not, maybe either I'll limit the rpms of the nitrous injection OR just have T/S don another reflash.

Gurgen - what's the latest on YOUR F/I quest??

Gene

 

Hey Guys, hey gene

First is first, Xenon and Kjb: guys, please clarify - I am not talkign about launching the car from rest and tripping up the VDC - I am talking just punching the gas from a rolling speed of 30 mph and tripping up the vdc that way. With a manual it is easier to do - you guys have shorter gear ratios - I am talking about doing so on a tall-geared AT car - which is much harder to do.

Gene - that's awesome - these t/c must be doing what they claimed they should do. I did overshoot it on the stall speed a little. Mine stalls at jst under 2600. Maybe 2800 would be better, who knows. But the low stall maybe the reason for the really tight TC - I love it. Cannot spin the tires much at all, but oh well. Will try that again today, as I got a 350z diff installed with a slightly shorter gear ratio and a VLSD!!!!.

My FI quests are delayed till February. This really sucks, but not much can be done. Have you guys heard of the two blown engines that happen today, one from a popcharger (#7) and one from Greddy TT (the very first Greddy TT installed commercially blows the engine - it must suck for their marketing team). But I'm glad that I am not headed on either of these routes...

Another funny things happened today. As mentioned above, I installed a 350Z rear diff, the whole case and everything. so I now have a VLSD and slightly shorter final drive ratio (3.5xx vs 3.3xx). After the install, unbeknownst to me, the two mecanics working on the car took it for a test drive after finishing the install. One was driving my G, the other one, a track edition 6MT 350z with a JWT popcharger, RT high flow cats, stillen exhaust - Not a stock Z by ay means. They raced off of a rolling start - THE TWO CARS WERE IN TOTAL DEAD HEAT all the way through redline (guessing 60mph)! And keep in mind, I still do NOT have the high flow cats he had (those are going in this week with a custom ECU tuning to follow) AND mine had the stock TC (50+lbs) and the the sotck diff assembly (100lbs) in the trunk, along with a full tank of gas! Damn this car is fast!

THAT just made my day!!!

Gurgen

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 12/22/03 07:11 PM.</EM></FONT></P>

 

Interesting Gurgen,

So it seems around 2600 is the right spot and you should have some more power due to new cats.

Its so sad regarding those blown motors in both cases. There were so many variable that could've gone wrong. I would highly recommend to do forged internals first (what Im doing with my Accord) with lower compression then boost can be raised over 8psi with proper tuning and intercooler is a must. FPR (fuel pressure regulator) has to supply enough fuel at both idle and WOT. In addition, 91 octane in CA and the rest 93 is a must with all FI applications with octane booster once a month and probably twice a month in cold weather.

Those who do not going to invest money towards better internals have to tune A/F ratio no more then 11.5-11.7 to be on a RICH side with maximum of 6-6.5 psi boost otherwise internals go BOOM.

And all those cases have to again properly tune with ECU to accept the unit all those gains.

2004 G35s auto (bone stock)
-----------------------------------
2002 s/c Accord V6 auto
so far best 1/4 mile - 13.9@101.8
coming soon: custom internals, cams, performance auto tranny w/LSD

 

Oh yeah my cats will be in tomorrow (hopefully) and be tuned on Friday at TS (hopefully). I KNOW for a fact that I will get at least 11 hp out of them (as that's what they got on a Z WITHOUT an ECU mod). With an ECU mod (with the A/F fattened back up to 12.5), another 2-5 are not out of the question.

Gurgen

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 12/23/03 02:12 PM.</EM></FONT></P>

 

2004 G35s auto (bone stock)
-----------------------------------
2002 s/c Accord V6 auto
so far best 1/4 mile - 13.9@101.8
coming soon: custom internals, cams, performance auto tranny w/LSD

 

Gurgen you've gone crazy with your car. I love it!!! lol. Keep up the modding and hope to see you at the meet.

--------------------------------------------------------------------------

2003 CB Coupe 6MT
Z-tube
Stillen Hi-flow

 

THanks man

I WILL MOST DEFINATELY be there. Hope to see you there!!! Thanks for the comment


Gurgen

 

Wats up Gurgen, I have few mod's on my car Injen CAI, Plenum, Technosquare a few other things.. With VDC off a couple of times going from first to second I have gotten the slip come on and reduced power to the throttle as it was on but this was on WET roads the couple of times... I think its because of the Injen or my shifting its an automatic but i also have a WRX modded and a manual so when I shift I take my foot of the pedal quick and shift up like Im use to so it gives me a big push into the gear. With the Injen I noticed when I got it a like lag between gear but then it kicks in and pulls. It could be for me the combination of taking my foot off throttle and stomping on it quick with the injens lag to give it that boost to the rear tires i have no idea but it could also be the wet road like i said.. Wet road is deff what enables it to d it soo... iLL G

Wat'ssss Realllyyyy Goooodddd!!!!!